Question: Who was the chairperson for the Social Democratic Party of Germany in 2004-3-21?
Paraphrase: In 2004-3-21, who was the chairperson of the Social Democratic Party of Germany?
SPARQL (Wikidata): SELECT ?obj WHERE { wd:Q49768 p:P488 ?s . ?s ps:P488 ?obj . ?s pq:P582 ?x filter(contains(YEAR(?x),'2004')) }